NIMH is supporting a 10-year investigation by our laboratory of the influence of psychosocial treatment on survival of women with metastatic breast cancer. We have recruited 125 metastatic breast cancer patients, and randomly assigned them either to one year of weekly supportive/expressive group therapy or to an educational control condition. This research is designed to replicate and extend our earlier finding that metastatic breast cancer patients randomly assigned to a year of weekly supportive/expressive therapy (SET) groups lived an average of 18 months longer than control patients (Spiegel et al., 1989). In this competing continuation we seek to accomplish two overall Aims: In Aim 1 we seek to complete follow-up of long-term survivors in our existing study. We currently have 73% overall mortality and must follow the sample until treatment/control differences in survival are analyzable at greater than 90% mortality. We have discovered an abnormality in diurnal variation of cortisol that predicts significantly shorter survival time, and plan to pursue our investigation of HPA dysfunction and breast cancer progression. In addition, we will examine the characteristics that distinguish long-term survivors, and mediators of treatment effects, specifically, analyses of in-group emotional expression and diurnal cortisol. In Aim 2 we seek to recruit a new, socioeconomically and ethnically diverse sample of 180 metastatic breast cancer patients with a range of PTSD. The sample will include 60 patients who meet diagnostic criteria for cancer-related posttraumatic stress disorder (PTSD), 60 patients with partial cancer-related PTSD, and 60 patients without a cancer-related PTSD diagnosis, as a comparison group. The subaims of this new study are to: A) evaluate the efficacy of SET on PTSD and other psychiatric Symptoms, quality of life, and survival in metastatic breast cancer patients with PTSD; B) examine hypothesized mediators of treatments effects (including emotional expression and cognitive processing of cancer-related stressors); and C) identify correlates of baseline adjustment (including SES, trauma/PTSD history, social constraints) and moderators of treatment response (including level of PTSD symptoms). The results of this study will provide evidence of the efficacy of group psychotherapy for metastatic breast cancer patients, including those with comorbid psychiatric (PTSD) symptoms, on the basis of proven psychiatric, psychosocial, and health benefits. The recruitment of this diverse sample of patients will also increase generalizability of findings regarding group psychotherapy outcome and its predictors.